i have read many posts here and experienced once sensei that really push the limits of what could be considered as training. I don;t think it is very common i certainly hope it isn't but how do people deal with it.
There seems to be a faction of people that think it is a good thing i.e. sensei locked me so hard that coudn;t train for a week, what a poweful guy.
So, I would think it would depend. If uke is giving himself/herself as a training aid to the nage and the nage is taking advantage of the openings purposefully left there by uke to aid in the training then it is definately wrong and in the wrong spirit of training.
The "old days" of training are just that, old. Times have changed. Training has changed. That being said I don't think that the old ways of training are bad but I do believe it has to be approached differently. I feel that in the old days those training trained for different reasons. Nowadays the reasons people train are far more diversified.
So, if the student knows the training format of the dojo and it is that of the "old ways" and still steps on the mat then shame on the student. If the student doesn't understand and is treated harshly then shame on the sensei.